SLLA665 April   2025 MCF8315A , MCF8315C , MCF8315C-Q1 , MCF8315D , MCF8316A , MCF8316C-Q1 , MCF8316D , MCF8329A , MCF8329A-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Open Loop and Handoff Stage
  5. 2EEPROM Configurations Affecting Open Loop to Closed Loop Handoff
  6. 3Open Loop to Closed Loop Handoff Tuning
    1. 3.1 Experimental Way to Tune Open Loop and Handoff Stage
      1. 3.1.1 Step-1: Initial Configuration
      2. 3.1.2 Step-2: Tuning of Parameters In Case Handoff is not Proper
        1. 3.1.2.1 Tuning of OL_ILIMIT
        2. 3.1.2.2 Tuning of Open Loop Acceleration Co-Efficient A1
        3. 3.1.2.3 Tuning of Handoff Thresholds
      3. 3.1.3 Step-3: Tuning of Handoff Configurations
  7. 4Optimum Handoff
    1. 4.1 Open Loop Time With the Recommended Settings
    2. 4.2 Open Loop Time by Following Optimum Handoff Steps
  8. 5Summary
  9. 6References

1 Introduction

The MCF83xx are three-phase BLDC motor drivers from Texas Instruments' BLDC motor driver family with sensor less field-oriented control (FOC) algorithm. The MCF83xx allows control of motor operation and system through the BRAKE, DRVOFF, DIR, EXT_CLK, EXT_WD, and SPEED/WAKE pins, and also provides signals for monitoring system variables, speed, fault, and phase current feedback through the DACOUT1, DACOUT2, FG, nFAULT, and SOX pins.

MCF83xx device is capable of spinning a BLDC motor in different spinning stages for reliable and controlled operation. Figure 1-1 describes the different stages of BLDC motor spinning.

Motor spinning begins from the pre-startup state by applying an ISD/BRAKE/Hiz command. The motor then transitions to the motor startup state to estimate the initial position. Next, the motor is operated in open-loop with constant current until the motor develops sufficient back EMF to estimate the speed and angle, then the motor enters closed-loop operation. After receiving a stop command, the motor switches to the configured stop option to stop in a controlled way.

BLDC Motor Spinning Stages Figure 1-1 BLDC Motor Spinning Stages